Support for Images without Alpha Channel?

[Webb Hinton]

As it stands ImageData requires an alpha channel. I think to new users it would be intuitive that you specify some kind of depth for the Image data you're trying to set, for example Rgb8, Rgba8, La8.

As it stands trying to set a simple .jpg to the clipboard with return an slice out of range error:

    let mut ctx = arboard::Clipboard::new().unwrap();
    let img = ImageReader::open("imgs/glitch_1.jpg").unwrap().decode().unwrap();
    let (w,h) = img.clone().into_rgb8().dimensions();
    let bytes = img.as_bytes();
    let img_data = arboard::ImageData{ width: w as usize, height: h as usize, bytes: bytes.into()};
    ctx.set_image(img_data).unwrap();

///for a 400x400 JPEG
thread 'main' panicked at 'range start index 638400 out of range for slice of length 480000',

If providing an alpha channel is a requirement of the OS, then maybe the readme/examples/docs could mention this, and provide some strategies for working around it, given that many people would assume support for common compression formats.

[Artúr Kovács]

I think to new users it would be intuitive that you specify some kind of depth for the Image data you're trying to set, for example Rgb8, Rgba8, La8.

It seems simpler to me if there's only one way to use it.

The example you showed should work if do it like this:

    let mut ctx = arboard::Clipboard::new().unwrap();
    let img = ImageReader::open("imgs/glitch_1.jpg").unwrap().decode().unwrap();
    let rgba8 = img.into_rgba8(); // Of course you can use `img.clone().into_rgba8()` if needed
    let (w,h) = rgba8.dimensions();
    let bytes = rgba8.into_raw();
    let img_data = arboard::ImageData{ width: w as usize, height: h as usize, bytes: bytes.into()};
    ctx.set_image(img_data).unwrap();

[Artúr Kovács]

If providing an alpha channel is a requirement of the OS, then maybe the readme/examples/docs could mention this

Providing an alpha channel is a requirement of the ImageData and as far as I can tell, the documentation is clear about this.

I should probably add an example for how to use the image crate together with this, but otherwise I think this issue can be closed. What do you think?